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Cited by 310Electrolyte and hormonal disordersPituitary Gland Disorders and TreatmentsNeuroendocrine regulation and behavior

The DOI matches its Crossref record; 40 of the 40 references it cites were found in a registry or an index; none of the 42 sources its claims cite is checked for support yet.

A Copeptin-Based Approach in the Diagnosis of Diabetes Insipidus

Open access

Abstract

BACKGROUND: The indirect water-deprivation test is the current reference standard for the diagnosis of diabetes insipidus. However, it is technically cumbersome to administer, and the results are often inaccurate. The current study compared the indirect water-deprivation test with direct detection of plasma copeptin, a precursor-derived surrogate of arginine vasopressin. METHODS: From 2013 to 2017, we recruited 156 patients with hypotonic polyuria at 11 medical centers to undergo both water-deprivation and hypertonic saline infusion tests. In the latter test, plasma copeptin was measured when the plasma sodium level had increased to at least 150 mmol per liter after infusion of hypertonic saline. The primary outcome was the overall diagnostic accuracy of each test as compared with the final reference diagnosis, which was determined on the basis of medical history, test results, and treatment response, with copeptin levels masked. RESULTS: A total of 144 patients underwent both tests. The final diagnosis was primary polydipsia in 82 patients (57%), central diabetes insipidus in 59 (41%), and nephrogenic diabetes insipidus in 3 (2%). Overall, among the 141 patients included in the analysis, the indirect water-deprivation test determined the correct diagnosis in 108 patients (diagnostic accuracy, 76.6%; 95% confidence interval [CI], 68.9 to 83.2), and the hypertonic saline infusion test (with a copeptin cutoff level of >4.9 pmol per liter) determined the correct diagnosis in 136 patients (96.5%; 95% CI, 92.1 to 98.6; P<0.001). The indirect water-deprivation test correctly distinguished primary polydipsia from partial central diabetes insipidus in 77 of 105 patients (73.3%; 95% CI, 63.9 to 81.2), and the hypertonic saline infusion test distinguished between the two conditions in 99 of 104 patients (95.2%; 95% CI, 89.4 to 98.1; adjusted P<0.001). One serious adverse event (desmopressin-induced hyponatremia that resulted in hospitalization) occurred during the water-deprivation test. CONCLUSIONS: The direct measurement of hypertonic saline-stimulated plasma copeptin had greater diagnostic accuracy than the water-deprivation test in patients with hypotonic polyuria. (Funded by the Swiss National Foundation and others; ClinicalTrials.gov number, NCT01940614 .).

Overview

CoChat Summary

TL;DR

In 141 analyzed patients with hypotonic polyuria, hypertonic saline–stimulated plasma copeptin measurement was more accurate than the indirect water-deprivation test for distinguishing central diabetes insipidus from primary polydipsia. The prespecified copeptin cutoff of >4.9 pmol/L achieved 96.5% overall diagnostic accuracy versus 76.6% for the indirect water-deprivation test.

Key findings

  • Hypertonic saline–stimulated copeptin (>4.9 pmol/L) correctly diagnosed 136 of 141 patients (96.5%; 95% CI, 92.1–98.6), compared with 108 of 141 (76.6%; 95% CI, 68.9–83.2) for the indirect water-deprivation test (P<0.001).
  • For the clinically important distinction of primary polydipsia from partial central diabetes insipidus, accuracy was 95.2% (99/104; 95% CI, 89.4–98.1) with hypertonic saline–stimulated copeptin versus 73.3% (77/105; 95% CI, 63.9–81.2) with the indirect water-deprivation test (adjusted P<0.001).
  • At the prespecified >4.9 pmol/L cutoff, sensitivity was 93.2% and specificity 100%; a post hoc >6.5 pmol/L cutoff had diagnostic accuracy 97.9%, sensitivity 94.9%, and specificity 100%.
  • Water-deprivation–stimulated copeptin had lower diagnostic accuracy than the indirect water-deprivation test (44.0%; 95% CI, 35.7–52.5 vs. 76.6%; 95% CI, 68.9–83.2), and one serious adverse event occurred during water deprivation: desmopressin-induced hyponatremia requiring hospitalization.

Methods

  • Prospective, international, multicenter study at 11 tertiary medical centers in Switzerland, Germany, and Brazil from July 2013 to June 2017; 156 patients aged ≥16 years with hypotonic polyuria or confirmed central diabetes insipidus were recruited, 144 underwent both tests, and 141 were included in the primary analysis.
  • Patients underwent an indirect water-deprivation test and a hypertonic saline infusion test on separate days; plasma copeptin was measured when plasma sodium reached at least 150 mmol/L after hypertonic saline.
  • Primary outcome was overall diagnostic accuracy versus a final reference diagnosis determined after study completion by two independent board-certified endocrinologists masked to copeptin levels, using medical history, water-deprivation test results, laboratory and imaging data, and 3-month treatment response; discordant diagnoses (4 of 144) were resolved with a third expert.

Limitations

  • The paper states there is no diagnostic standard for hypotonic polyuria and that the reference diagnosis incorporated indirect water-deprivation test results, which may have caused incorporation bias; if present, this may have overestimated the diagnostic performance of the water-deprivation test.
  • The paper notes caveats for hypertonic saline infusion: more adverse effects were reported than with water deprivation, close sodium monitoring was required, and female patients appeared more vulnerable to marked sodium increases; the test also required achieving a diagnostically meaningful hyperosmotic sodium level.
  • Evident from the text: nephrogenic diabetes insipidus was assessed only descriptively in 3 patients, so performance in that group is not established; symptom burden and preference relied on patient-rated visual-analogue scores.

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Integrity signals

Registry

Crossref · 10.1056/nejmoa1803760

Cites

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Citations

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  1. Rose BD Post TW. Clinical physiology of acid-base and electrolyte disorders. 5th ed. New York: McGraw-Hill 2001:748-767.

Cited by

Items 101–200 of 310

Metadata

Authors
Fenske, W., Refardt, J., Chifu, I., Schnyder, I., Winzeler, B., Drummond, J., Ribeiro-Oliveira, A., Drescher, T., Bilz, S., Vogt, D. R., Malzahn, U., Kroiss, M., Christ, E., Henzen, C., Fischli, S., Tönjes, A., Mueller, B., Schopohl, J., Flitsch, J., Brabant, G., Fassnacht, M., & Christ-Crain, M.
Affiliations
  • University of Würzburg (DE)
  • Universidade Federal de Minas Gerais (BR)
  • From the University of Leipzig, Department of Endocrinology and Nephrology (W.F., A.T.), and Leipzig University Medical Center, Integrated Research and Treatment Center Adiposity Diseases (W.F.), Leipzig, the Department of Internal Medicine I, Division of Endocrinology and Diabetes, University Hospital, University of Würzburg (I.C., M.K., M.F.), and the Clinical Trial Center (U.M.) and Central Laboratory (M.F.), University Hospital Würzburg, Würzburg, Medizinische Klinik und Poliklinik IV, Ludwig...
  • University of Basel (CH)
Venue
New England Journal of Medicine
Published
2018-08-02
Volume
379
Issue
5
Pages
428-439
ISSN
  • 0028-4793 (ISSN-L)
  • 1533-4406
OpenAlex
W2886697375
Cited by
310
References
40
Citations by year
2026: 30 · 2025: 53 · 2024: 41 · 2023: 33 · 2022: 34 · 2021: 52 · 2020: 29 · 2019: 25 · 2018: 11
FWCI
24.10
Type
journal article
Language
en
Open access
Locations
  • New England Journal of Medicine (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Thermo Fisher Scientific (none, laboratory measurement of copeptin)
  • Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (SNF-162608)
  • Deutsche Forschungsgemeinschaft (AOBJ: 624808)
  • Bundesministerium für Bildung und Forschung (FKZ:01EO1501)
Topics
  • Health Sciences › Medicine › Nephrology › Electrolyte and hormonal disorders
  • Health Sciences › Medicine › Endocrinology, Diabetes and Metabolism › Pituitary Gland Disorders and Treatments
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Neuroendocrine regulation and behavior
Keywords
copeptin, water deprivation test, vasopressin, central diabetes insipidus, nephrogenic diabetes insipidus, primary polydipsia, diagnostic accuracy
MeSH terms
Adult, Deamino Arginine Vasopressin, Diabetes Insipidus, Diagnosis, Differential, Female, Glycopeptides, Humans, Hyponatremia, Male, Middle Aged, Osmolar Concentration, Polyuria, ROC Curve, Saline Solution, Hypertonic, Sensitivity and Specificity, Urine, Water Deprivation, Polydipsia

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